Flushing arrangement

ABSTRACT

A flushing arrangement for flushing a surface of a wet-mateable connector for subsea use is provided. The flushing arrangement has a cartridge adapted to form a chamber around the surface to be flushed prior to flushing. The cartridge has a sealing portion adapted to be sealed against a part of the connector. An inlet port for receiving a fluid from a fluid source and an outlet port for discharging a fluid are provided. Plural flow channels are formed in the cartridge, the plural flow channels comprising flow channels providing a fluid connection between the inlet port and the chamber for enabling a flow of fluid into the chamber and flow channels providing a fluid connection between the chamber and the outlet port for enabling a flow of medium out of the chamber.

PRIORITY STATEMENT

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/EP2014/070380 which has anInternational filing date of Sep. 24, 2014, which designated the UnitedStates of America and which claims priority to European patentapplication number EP13186722.8 filed Sep. 30, 2013, the entire contentsof which are hereby incorporated herein by reference.

FIELD

An embodiment of the invention generally relates to a flushingarrangement and in particular to a flushing arrangement for a subseaconnector.

BACKGROUND

Several applications are known in which electrical connections need tobe provided underwater. Examples include a subsea installation for theproduction of hydrocarbons from a subsea well, in which differentcomponents of the subsea installation may need to be connectedelectrically. Such connections may for example comprise a connectionfrom a topside installation, such as a floating or fixed platform, orfrom an onshore site to a subsea component, e. g. by an umbilical or asubsea cable. Other connections include electrical connections betweendifferent type of subsea equipment, such as a connection between asubsea transformer and subsea switchgear, electrical connections to apump or a compressor or the like.

For providing an underwater electrical connection, wet-mateableconnectors are known which can be mated underwater. Although such typeof connectors are generally more complex than corresponding dry-mateconnectors, which have to be mated above water, wet-mateable connectorshave several advantages. Components of the subsea installation can forexample be disconnected and can be retrieved for servicing or exchange,additional components may be connected to an existing subseainstallation, electric connections can be provided to a subsea structureafter installation thereof at the ocean floor, and the like.

A general problem with such subsea connectors is the corrosive characterof seawater. Seawater generally causes corrosion and degradation ofmaterials exposed thereto. Exposed surfaces are furthermore prone to thegrowth of organic material thereon, such as algae, bacteria and thelike. Such marine growth can be detrimental to the functioning of thesubsea connector.

Accordingly, in order to protect exposed surfaces when the connectorparts are unmated (e.g. when a connector part is unplugged and not inuse), it is known to use “dummy plugs” or “dummy receptacles” to whichthe connector part is mated. Components of the connector part, such as apin, can thus be protected effectively from the surrounding seawater.Such dummy plug generally needs to include all features of a standardplug at its connecting section, but does not connect to a cable but onlyto a dummy gland, which isolates the pin from the metal works and whichmay be used for electrical testing. As such fully functional dummy plugmay need to be provided for each un-mated connector part, significantcosts can be incurred.

Furthermore, it is known to flush connector parts before mating byfiltered seawater to remove debris, such as described in EP 2520757 A2.Even with such prior cleaning of the contact portions of the connector,the electrical contact provided by the connector may be degraded due tothe exposure of the contact surfaces to seawater.

In particular at high voltages, e. g. voltages above 5,000 V, 10,000 Vor even 30,000 V, even a minor degradation of the electrical contactprovided by the connector may have significant consequences, such as areduced lifetime of the connection, or even a failure in the connection.The same applies to optical connections, in which marine growth ordebris may sincerely affect the quality of the connection or may evenresult in the connection not being established.

It is thus desirable to at least reduce the effects of seawater on aconnection provided by such wet-mateable connector. It is desirable toprovide a connection in a reliable and effective way. Furthermore, thecomplexity of the connector should not be increased significantly. Also,it is desirable that the connector parts remains operational over arelatively large number of mating/demating cycles and have a relativelylong lifetime. It is in particular desirable to provide an improvedconnector for subsea use in a cost-efficient way.

SUMMARY

The inventors have recognized that there is a need to obviate at leastsome of the drawbacks mentioned above and in particular to reduce theeffect of seawater on the operation of a wet-mateable connector.

The claims describe embodiments of the invention.

According to an embodiment of the invention, a connector for subsea useis provided. The connector has a first connector part and a secondconnector part adapted to be mated subsea. The connector comprises afirst coupling portion arranged in the first connector part and a secondcoupling portion arranged in the second connector part. The first andsecond coupling portions are configured to be brought into engagementfor establishing an electrical or optical connection when the firstconnector part and the second connector part are mated (the connectionmay for example be established in a fully mated position). The connectorfurther comprises a first protection assembly forming part of the firstconnector part, the first protection assembly being configured toprevent the exposure of the first coupling portion to seawater when theconnector is unmated and deployed subsea, and a second protectionassembly forming part of the second connector part, the secondprotection assembly being configured to prevent the exposure of thesecond coupling portion to seawater when the connector is unmated anddeployed subsea. The connector further comprises a flushing arrangementconfigured to enable a flushing of a surface of at least one of thefirst and second protection assemblies.

According to a further embodiment, a subsea connection system comprisinga connector in any of the above described configurations is provided.The subsea connection system further comprises a mating tool forassisting the mating of the first connector part and the secondconnector part. The mating tool comprises a first fluid port connectableto an inlet port of the flushing arrangement of the connector forproviding a non-seawater medium to the flushing arrangement and a secondfluid port connectable to an outlet port of the flushing arrangement forreceiving a fluid from the flushing arrangement. By way of such matingtool, the mating procedure and the flushing of the surface of theprotection assembly of the connector can be performed in an efficientway.

A further embodiment of the invention provides a method of mating afirst connector part and a second connector part of a connector in asubsea environment. The method comprises the step of providing the firstand second connector parts in an unmated state in which a first couplingportion arranged in the first connector part is protected from seawaterby a first protection assembly forming part of the first connector partand in which a second coupling portion arranged in the second connectorpart is protected from seawater by a second protection assembly formingpart of the second connector part. Further steps of the method includebringing the first and second connector parts into a first matedposition in which the first coupling portion and the second couplingportion are disengaged, flushing a surface of at least one of the firstand second protection assemblies by way of a flushing arrangement andbringing the first and second connector parts into a second matedposition in which the first and second coupling portions are inengagement to establish an electrical or optical connection. By way ofsuch method, advantages similar to the ones outlined further above withrespect to the connector may be achieved. In particular, the first andsecond coupling portions may be brought into engagement without beingexposed to seawater, and the danger of dragging seawater into the firstor second protection assemblies is further reduced.

According to a further aspect of the invention, a flushing arrangementfor flushing a surface of a wet-mateable connector for subsea use isprovided. The flushing arrangement comprises a cartridge adapted to forma chamber around the surface to be flushed prior to flushing. Thecartridge has a sealing portion adapted to be sealed against a part ofthe connector, it may be sealed against the surface to be flushed. Theflushing arrangement further comprises an inlet port for receiving afluid from a fluid source and an outlet port for discharging a fluid.Plural flow channels are formed in the cartridge, and the plural flowchannels comprise flow channels providing a fluid connection between theinlet port and the chamber for enabling a flow of fluid into the chamberand flow channels providing a fluid connection between the chamber andthe outlet port for enabling a flow of a medium out of the chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages of the invention willbecome further apparent from the following detailed description read inconjunction with the accompanying drawings. In the drawings, likereference numerals refer to like elements.

FIG. 1 is a schematic drawing showing a sectional view of a connectoraccording to an embodiment of the invention in an unmated state.

FIG. 2 is a schematic drawing showing a sectional view of the connectorof FIG. 1 in a first mated state.

FIG. 3 is a schematic drawing showing a sectional view of the connectorof FIGS. 1 and 2 in a second mated state.

FIG. 4 is a schematic drawing showing a subsea connection systemaccording to an embodiment of the invention.

FIGS. 5A, 5B and 5C are schematic drawings illustrating a connectoraccording to a further embodiment of the invention and showing detailsof the flushing arrangement according to an embodiment of the invention.

FIG. 6 is a schematic drawing showing details of the connector of FIG.5A in the first mated state.

FIG. 7A is a schematic drawing showing a sectional side view of acartridge of a flushing arrangement according to an embodiment of theinvention.

FIG. 7B is a schematic drawing showing a sectional top view of acartridge of a flushing arrangement according to an embodiment of theinvention.

FIG. 7C is a schematic drawing showing a top view of a cartridge of aflushing arrangement according to an embodiment of the invention.

FIG. 8 is a flow diagram illustrating a method according to anembodiment of the invention.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

According to an embodiment of the invention, a connector for subsea useis provided. The connector has a first connector part and a secondconnector part adapted to be mated subsea. The connector comprises afirst coupling portion arranged in the first connector part and a secondcoupling portion arranged in the second connector part. The first andsecond coupling portions are configured to be brought into engagementfor establishing an electrical or optical connection when the firstconnector part and the second connector part are mated (the connectionmay for example be established in a fully mated position). The connectorfurther comprises a first protection assembly forming part of the firstconnector part, the first protection assembly being configured toprevent the exposure of the first coupling portion to seawater when theconnector is unmated and deployed subsea, and a second protectionassembly forming part of the second connector part, the secondprotection assembly being configured to prevent the exposure of thesecond coupling portion to seawater when the connector is unmated anddeployed subsea. The connector further comprises a flushing arrangementconfigured to enable a flushing of a surface of at least one of thefirst and second protection assemblies.

Such configuration may achieve that neither in an unmated state, norduring mating; the first and second coupling portions are exposed toseawater. For providing an electrical or optical connection duringmating, the first and second protection assemblies may need to exposethe first and second coupling portions. By flushing the surface of thefirst and/or second protection assembly, it can be prevented thatseawater wetting such surface of the respective protection assembly canenter or is dragged into one of the first or second protectionassemblies and thus comes into contact with a coupling portion. Theflushing arrangement may in particular be configured to perform theflushing so as to prevent ingress of seawater into the first or secondprotection assemblies during mating. The coupling portion may be anelectrical contact portion, such as a contact ring on a pin or a contactsleeve, or it may be an optical coupling, or may comprise a combinationthereof.

In an embodiment, the surface which is to be flushed comprises a surfacewhich enters the first protection assembly or the second protectionassembly when the first coupling portion is brought into engagement withthe second coupling portion. It may for example a front face of a pin orshuttle pin of the first or second connector part. By flushing suchsurface, it may be prevented that seawater adhering to the surface isallowed to enter the protection assembly.

In an embodiment, the surface comprises an exposed surface of the firstand/or second protection assembly which is exposed to seawater when thefirst connector part and the second connector part are unmated anddeployed subsea. The flushing arrangement may be configured so as toenable the displacement of the seawater at the exposed surface by anon-seawater medium prior to engaging the first coupling portion and thesecond coupling portion. The flushing arrangement may for example beconfigured to form a chamber around such exposed surface so as to enablethe replacement of seawater at the exposed surface.

In an embodiment, the first and second protection assemblies and theflushing arrangement are configured such that a flushing operationperformed by the flushing arrangement does not flush the first and thesecond coupling portions. As the first and second coupling portions arenot exposed to seawater, the flushing may be restricted to the flushingof surfaces of the first and second protection assemblies. This does notexclude that during mating, one of the coupling portions may movethrough a chamber formed by the flushing arrangement.

The non-seawater medium may be a fluid, in particular a predeterminedliquid, preferably a dielectric liquid. An example of the non-seawatermedium is oil, e. g. silicone oil, or the like. Such type ofnon-seawater medium will generally not have a degrading effect on theconnection to be established by the first and second coupling portions.

In an embodiment, the first connector part comprises a first element ofthe flushing arrangement and the second connector part comprises asecond element of the flushing arrangement, wherein the first elementand the second element form a chamber when the first connector part ismated with the second connector part in a first mated position (or matedstate). The surface to be flushed is located within the chamber, and theflushing arrangement is configured to enable the filling of the chamberwith a non-seawater medium. In such configuration, the flushingarrangement may form a chamber that is liquid tight sealed against theenvironment, in particular against ambient seawater. Such chamber canenable the exchange of medium in the chamber, for example the exchangeof seawater by a non-seawater medium or the exchange of suchnon-seawater medium by seawater.

The exposed surface of the first and/or second protection assemblies andthe first and second elements of the flushing arrangement mayparticipate in forming the chamber, i.e. the exposed surface may formpart of a wall or boundary of the chamber.

The first and/or second element of the flushing arrangement may formpart of the first and/or second connector part, respectively. The firstor second element may for example be part of a housing of the respectiveconnector part or part of the protection assembly of the respectiveconnector part.

The flushing arrangement may in some embodiments comprise a cartridge.In some embodiments, the first or second element of the flushingarrangement may be such cartridge, and the other of the first or secondelements may be part of the respective connector part. As an example,one element of the flushing arrangement may be a cartridge and the otherelement of the flushing arrangement may be a surface on a connectorpart, e. g. a front surface of a plug part or a front surface of theprotection assembly of one of the first or second connector parts. Inother embodiments, the cartridge may have a first cartridge part and asecond cartridge part. The first and second elements of the flushingmechanism may be first and second cartridge parts of the cartridge.

Possible configurations of such flushing arrangement including acartridge are described herein further below. The flushing arrangementof the present embodiments may have any of the below describedconfigurations.

The first mated position may be a flushing position in which theflushing arrangement forms the chamber and in which flushing of thechamber is performed; it may also be termed “initial mating position”. Asecond mated position may be a position in which the first and secondconnector parts are in full engagement, and in which the connectionbetween the first and second coupling portions is made; it may also betermed “fully mated position”.

In an embodiment, the first connector part comprises a pin, the firstelement of the flushing mechanism having a first opening in which afront portion of the pin is located in the first mated position. Thesurface that is to be flushed is a surface on the front portion of thepin. The second element of the flushing arrangement may have a secondopening formed so as to allow the passage of the pin through the secondopening when the first connector part is moved from the first matedposition into a second mated position.

In such configuration, it is possible to flush a front face of the pinwithin the above mentioned chamber, and thereafter move the pin throughthe second element of the flushing arrangement into the secondprotection assembly for establishing the connection. The front portionof the pin may also be termed “pin tip”.

The pin may for example have a cylindrical outer surface, and the firstopening in the first element and the second opening in the secondelement of the flushing arrangement may have an inner cylindricalsurface each comprising a circumferential seal for sealing against theouter cylindrical surface of the pin. The seal may for example be agland type seal, a gland seal, a piston seal or the like.

The first element of the flushing arrangement may have an annular shapeand may be mechanically coupled to a sliding carriage. The first elementand the sliding carriage may be configured to be slidable along the pinof the first connector part into a second mated position, with an innersurface of the annular first element being sealed against a frontportion of the pin in the unmated position and in the first matedposition. By coupling the first element of the flushing arrangement tothe sliding carriage, it is possible that the pin is protected from thesubsea environment in an unmated position, while the pin is exposedduring mating so that the pin can enter the second protection assemblyof the second connector part. During mating, the pin passes through theopening in the annular first element when the annular first element andthe sliding carriage slide into the second mated position.

In the unmated position, the annular first element of the flushingarrangement may in some embodiments protrude from the pin's front faceto form a recess, which later forms the chamber for flushing when thetwo connector parts are brought into the first mated state. In otherembodiments, the annular first element may be retracted such that theannular first element and the pin's front face are essentially flush orsuch that the pin's front face protrudes from the first element. In suchstate, flow channels which may have ports in an inner cylindrical faceof the annular element, may be protected by the pin from the subseaenvironment when in the unmated position.

In an embodiment, at least one of the first and second elements has aseal adapted to be sealed against the other of the first and secondelements. The seal is configured to provide a liquid tight sealing ofthe chamber in the first mated position of the first and secondconnector parts. As an example, the first and second elements may haveannular faces facing each other in the first mated position, and theseal may be provided as a circular seal between these faces, for examplein the form of an O-ring. The seal may be made of a plastic material, inparticular a polymer material, such as PEEK (polyetheretherketone),preferably PTFE (polytetrafluoroethylene) loaded PEEK.

The flushing arrangement may comprise an inlet port for introducing thenon-seawater medium into the chamber and an outlet port for collecting afluid leaving the chamber. As an example, the inlet port and the outletport may be provided in the first element of the flushing arrangement.Different configurations are conceivable in other embodiments, forexample providing the inlet port and the outlet port in the secondelement.

The flushing arrangement may furthermore comprise a collection tank forcollecting a fluid leaving the chamber, e. g. via the outlet port.Accordingly, if a non-seawater medium, such as a dielectric liquid, inparticular oil, is introduced into the chamber, medium spilling out ofthe chamber during flushing, or medium being flushed out of the chamberby seawater prior to de-mating can be collected in the collection tankso as to prevent a pollution of the surrounding environment.

In an embodiment, the first and/or second elements of the flushingarrangement are made of a plastic material, in particular athermoplastic material, preferably a polymer material, such as PEEK.Such configuration of the first and second elements of the flushingarrangement allows a simple and lightweight construction of the flushingarrangement, which does not require extensive modification of existingconnectors for being used therewith. Furthermore, it allows for theintroduction of complex flow structures into the flushing arrangementwhich can be shaped so as to improve the removal of seawater from thechamber and thus the flushing of the above mentioned surface.

In an embodiment, at least one of the first and second elements of theflushing arrangement is radially floating to facilitate alignment of therespective first or second element of the flushing arrangement with apin of the first connector part during mating.

The second element of the flushing arrangement may for example beprovided in a cylindrical recess in a plug body of the second connectorpart. Such cylindrical recess may have an inner diameter which isslightly larger than the diameter of an outer cylindrical face of thesecond element so that the second element can to a certain extent changeits radial position when mounted to the front portion of the plug body.When moving from the first mated position into the second matedposition, the pin may move towards the second element, and the secondelement can, due to the floating mount, align itself with the frontportion of the pin so that the pin can enter and pass through theopening in the second element of the flushing arrangement. By providingsuch tolerance, the production of the connector may be facilitated, anda more reliable mating may be achieved.

In an embodiment, at least one of the first and second elements of theflushing arrangement may be provided with flow channels which areconfigured so as to achieve a flow without stagnation points inside thechamber during flushing. Accordingly, with such flow, seawater fillingthe chamber may be flushed out almost completely by the non-seawatermedium prior to mating. Stagnation point generally refers to a point ina flow at which the local velocity of the fluid is about zero. Byproviding a flow without stagnation points, the possibility of havinglocations or vortices at which seawater is trapped during flushing isreduced, thereby improving the quality of flushing.

In an embodiment, the first protection assembly comprises a frontportion of a pin and the second protection assembly comprises a shuttlepin. The surface to be flushed may comprise at least the front face ofthe pin and a front face of the shuttle pin, which generally are exposedsurfaces which are exposed to seawater when the first connector part andthe second connector parts are unmated and deployed subsea. The flushingarrangement may be configured to enable a flushing of at least the frontface of the pin and the front face of the shuttle pin prior to engagingthe first coupling portion and the second coupling portion.

The chamber for flushing may for example be formed by the tip of thepin, the tip of the shuttle pin, and the first and second elements ofthe flushing arrangement. By flushing the front face of the pin and thefront face of the shuttle pin, it can be prevented that seawater adheresor is trapped between the two faces when they engage during mating.Seawater may thus be prevented from entering the second protectionassembly when the pin and the shuttle pin are together pushed into thesecond protection assembly, in particular into the plug body of thesecond connector part. Protection of the coupling elements from seawatercan thus be improved.

In an embodiment, the connector is configured to have a first matedposition in which the first connector part engages the second connectorpart, and in which the flushing arrangement forms a chamber for flushingthe above mentioned surface. The connector may further have a secondmated position in which the connector can be brought by axial movementof the first and second connector parts towards each other (they are forexample moved into further engagement). In the first mated position, thefirst and second coupling portions are disengaged, and in the secondmated position, the first and second coupling portions are inengagement. By providing the connector in such configuration, theconnector itself does not need to comprise any actuators or movablemechanical elements for engaging the first and second coupling portions.Rather, it is possible to move the connector into the second matedposition, in particular into the fully mated position, by a forceapplied externally, e. g. via an ROV or a mounting tool. The complexityof the connector can thus be kept relatively low.

In an embodiment, the first connector part comprises a pin, a frontportion of the pin being exposed to seawater when the first connectorpart is deployed subsea. The first protection assembly may comprise asliding carriage which is in sealing engagement with the front portionof the pin in an unmated state of the first connector part, and thefront portion of the pin itself. The first coupling portion is arrangedon the pin rearwardly of the front portion of the pin, and the slidingcarriage is slidable along the pin such that it is movable between anunmated position in which the first coupling portion is protected fromseawater by the sliding carriage and a mated position in which thesliding carriage is positioned rearwardly of the first coupling portion.Accordingly, by way of the sliding carriage, it is possible to exposethe first coupling portion so that it can make contact with the secondcoupling portion of the other connector part. The first coupling portionis generally exposed only during mating, so that it does not get intocontact with the subsea environment, but rather enters into the secondprotection assembly of the second connector part, where it is againprotected. Furthermore, a flexible diaphragm may be provided between thesliding carriage and a supporting portion of the first connector part,in particular a support of the pin. Such flexible diaphragm may provideprotection from the subsea environment for the rear portion of the pinand may furthermore allow the sliding carriage to move backwardly inorder to expose the first coupling portion. The flexible diaphragm mayfor example be filled with a liquid, such as a dielectric liquid.

In an embodiment, the second connector part is a plug part having a plugbody with a front portion (may also be termed “plug nose”), and thesecond protection assembly comprises a shuttle pin having a frontportion (also termed “shuttle pin tip”) and at least a front portion ofthe plug body. The front portion of the plug body and the front portionof the shuttle pin are exposed to seawater when the second connectorpart is deployed subsea in an unmated state of the second connectorpart. The front portion of the plug body is in sealing engagement withthe front portion of the shuttle pin, so that ingress of seawater intothe plug body may be prevented. The second coupling portion is locatedrearwardly of the front portion of the shuttle pin within the plug body.Protection of the coupling portion from subsea environment may thus beachieved. The front portion of the shuttle pin is movable into the plugbody into a position rearwardly of the second coupling portion. Suchconfiguration allows a pin of the first connector part to enter the plugbody and allows the first coupling portion to get into contact with thesecond coupling portion. Movement of the shuttle pin to a positionrearwardly of the second coupling portion essentially exposes the secondcoupling portion to the pin tip.

The second coupling portion may, when providing an electricalconnection, for example be provided in the form of a sleeve-likecomponent. It may for example be provided in form of a socket contact. Aphysical coupling between the coupling portion on the pin tip and suchsocket contact may for example be achieved by some type of compliant orspring-loaded component, so as to achieve a good electrical connectionand allow for many make and break cycles. As an example, a Multilamcontact may be used.

The outer diameter of the pin of the first connector part mayessentially be the same as the outer diameter of the receptacle pin ofthe second connector part. Correspondingly, the inner diameter of theopening in the first element of the flushing arrangement may besubstantially similar to the inner diameter of the opening in the secondelement of the flushing arrangement. This may ensure proper sealingagainst the outer surface of the pin when the pin moves through thefirst and second elements of the flushing arrangement and into the plugbody of the second connector part during mating.

The flushing arrangement may furthermore comprise an excess pressurerelieve valve. In such configuration, it can be ensured that thepressure within a chamber formed by the flushing arrangement stays belowa predetermined pressure threshold. The threshold may for example be setso as to prevent the pressure from pushing the shuttle pin into the plugbody of the second connector part.

The flushing arrangement may furthermore be provided with a volumecompensator. The volume compensator may be configured to compensatevolume changes of a medium within the chamber or of the chamber itself.By such volume compensator, it can be ensured that there is nosignificant pressure increase when the pin of the first connector partmoves into the chamber formed by the flushing arrangement. When movingfrom the first mated position into the second mated position, the pindisplaces medium located in the chamber formed by the flushingarrangement, and the volume compensator may take up such displacedmedium. Several different configurations of the volume compensator areconceivable. It may for example comprise a flexible element, such as abellow, bladder or the like which is in fluid communication with thevolume inside the chamber, or it may comprise arrangements coupled to aninlet port or an outlet port of the flushing arrangement which allowliquid from within the chamber to be disposed through the respectiveport, e.g. a pressure relieve valve or the like.

The connector can in some embodiments be configured to be mateablewithout flushing. Accordingly, in less critical applications, the firstand second connector parts may be mated without performing the flushingoperation, thereby facilitating the mating procedure. By way of thefirst and second protection assemblies, exposure of the first and secondcoupling portions to seawater is nevertheless kept very low.

According to a further embodiment, a subsea connection system comprisinga connector in any of the above described configurations is provided.The subsea connection system further comprises a mating tool forassisting the mating of the first connector part and the secondconnector part. The mating tool comprises a first fluid port connectableto an inlet port of the flushing arrangement of the connector forproviding a non-seawater medium to the flushing arrangement and a secondfluid port connectable to an outlet port of the flushing arrangement forreceiving a fluid from the flushing arrangement. By way of such matingtool, the mating procedure and the flushing of the surface of theprotection assembly of the connector can be performed in an efficientway.

In an embodiment, the tool may be a tool of a remotely operated vehicle(ROV), or may be part of such ROV. Mating of the first and secondconnector parts may thus be performed even at great water depths, e. g.in excess of 2.000 m.

In an embodiment, the subsea connection system further comprises acollection tank for collecting a fluid received from the flushingarrangement. As an example, when flushing out a chamber formed by theflushing arrangement with a non-seawater medium, or when replacingnon-seawater medium within such chamber by seawater (e. g. prior tode-mating), the fluid coming out of the chamber can be collected,thereby preventing the pollution of the subsea environment.

In an embodiment, the mating tool comprises a pump adapted to provide anelevated pressure at the first fluid port for flowing a fluid into achamber of the flushing arrangement. The fluid may for example be theabove mentioned non-seawater medium, which is flushed into the chamberprior to mating, or it may be seawater, which can be flushed into thechamber prior to de-mating or after completion of the mating cycle.

In another embodiment, the mating tool may comprise a pump adapted toprovide a reduced pressure at the second fluid port for removing a fluidfrom a chamber of the flushing arrangement. In such configuration, thefluid inside the chamber of the flushing arrangement may essentially besucked out, thereby avoiding problems which may occur when increasingfluid pressure inside the chamber. Again, such configuration may be usedto replace seawater inside the chamber by a non-seawater medium, or maybe used to displace a non-seawater medium, such as a dielectric liquid,by seawater prior to de-mating or after completion of the mating cycle.

In a further embodiment, the mating tool may comprise a holdingmechanism adapted to hold the first connector part and the secondconnector part in a first mated position in which the flushing of thesurface by the flushing arrangement can be performed. With a subseaconnection system in such configuration, it is not necessary to providethe first and second connector parts with additional locking mechanismsfor locking them together in the first mated position when flushing theexposed surfaces.

A further embodiment of the invention provides a method of mating afirst connector part and a second connector part of a connector in asubsea environment. The method comprises the step of providing the firstand second connector parts in an unmated state in which a first couplingportion arranged in the first connector part is protected from seawaterby a first protection assembly forming part of the first connector partand in which a second coupling portion arranged in the second connectorpart is protected from seawater by a second protection assembly formingpart of the second connector part. Further steps of the method includebringing the first and second connector parts into a first matedposition in which the first coupling portion and the second couplingportion are disengaged, flushing a surface of at least one of the firstand second protection assemblies by way of a flushing arrangement andbringing the first and second connector parts into a second matedposition in which the first and second coupling portions are inengagement to establish an electrical or optical connection. By way ofsuch method, advantages similar to the ones outlined further above withrespect to the connector may be achieved. In particular, the first andsecond coupling portions may be brought into engagement without beingexposed to seawater, and the danger of dragging seawater into the firstor second protection assemblies is further reduced.

In an embodiment, the step of bringing the first and second connectorparts into a first mated position comprises forming a chamber around thesurface of the respective protection assembly by way of a first elementand a second element of the flushing arrangement. This may for examplebe done by providing a cartridge as the first or second element andsealing the cartridge against the other of the first or second element,e.g. against a front portion of the respective connector part or againstanother cartridge part. The step of flushing may comprise substituting afluid in the chamber by a non-seawater medium. An effective removal ofthe seawater from the surface to be flushed may thus be achieved.

In an embodiment, the step of bringing the first and second connectorparts into the second mated position may comprise pushing a pin of thefirst connector part through the chamber into engagement with a shuttlepin of the second connector part and into a plug body of the secondconnector part by axially moving the first connector part and the secondconnector part towards each other. By using such method for bringing theconnector into the second mated position, a connector of relatively lowcomplexity can be used, and the mating procedure is facilitated.

Embodiments of the method may be performed by using a connector in anyof the above outlined configurations. Similarly, the above describedconnector may be configured so as to perform methods according to any ofthe embodiments described herein.

According to a further aspect of the invention, a flushing arrangementfor flushing a surface of a wet-mateable connector for subsea use isprovided. The flushing arrangement comprises a cartridge adapted to forma chamber around the surface to be flushed prior to flushing. Thecartridge has a sealing portion adapted to be sealed against a part ofthe connector, it may be sealed against the surface to be flushed. Theflushing arrangement further comprises an inlet port for receiving afluid from a fluid source and an outlet port for discharging a fluid.Plural flow channels are formed in the cartridge, and the plural flowchannels comprise flow channels providing a fluid connection between theinlet port and the chamber for enabling a flow of fluid into the chamberand flow channels providing a fluid connection between the chamber andthe outlet port for enabling a flow of a medium out of the chamber.

Such flushing arrangement may allow a connector to be provided with aflushing mechanism in an efficient and relatively cost-efficient way.Furthermore, only minor modifications may be necessary for providingsuch connector with a flushing mechanism.

The cartridge may not form part of a housing of the first or secondconnector part of the connector. When the chamber for flushing is formedby the cartridge, the flushing arrangement is configured such that thechamber is sealed in a liquid tight manner against an ambient medium,i.e. against surrounding seawater when deployed subsea.

In an embodiment, the plural flow channels are configured to generate aflow without stagnation points in the chamber when providing a fluid viathe inlet port. By such configuration of the flow channels, an efficientand substantially complete removal of a fluid located within the chamberbecomes possible. In particular, no fluid, such as seawater, is trappedif a flow without stagnation points is generated by the flow channels.Furthermore, the flow channels may be configured to create an at leastpartially turbulent flow in the chamber for flushing the surface.

The cartridge is adapted to be capable of forming a chamber around thesurface to be flushed. In use, the cartridge may thus first be broughtinto a state in which the chamber is formed and may then be used forflushing the surface.

In an embodiment, the sealing portion is provided on an innercylindrical face of the cartridge and is adapted to provide sealingagainst an outer cylindrical face of a pin of a connector part of theconnector. The sealing portion may for example be used to providesealing against a front portion of a pin, in particular a receptacle pinprovided in a receptacle part of the connector, or against a frontportion of a shuttle pin of a plug part of the connector.

In some embodiments, the cartridge may be made of a single piece whichis sealed against a portion of a connector part to form the abovementioned chamber.

In other embodiments, the cartridge has a first cartridge part adaptedto be mounted to a first connector part and a second cartridge partadapted to be mounted to a second connector part of the connector. Theflushing arrangement may further comprise a sealing element configuredto provide a liquid tight seal between the first cartridge part and thesecond cartridge part when forming the chamber. Accordingly, by bringingthe first connector part and the second part together, e. g. in a firstmated state, the chamber for flushing may be formed by the firstcartridge part and the second cartridge part. These may correspond tothe above mentioned first element and second element of the flushingarrangement, and may be configured correspondingly.

As an example, the seal may be made of a plastic material, in particulara polymer material, such as PEEK, preferably PTFE loaded PEEK.

In an embodiment, the sealing portion and the inner cylindrical faceform part of the first cartridge part, and the second cartridge part maycomprise a second inner cylindrical face and a second sealing portionadapted to provide sealing against an outer cylindrical face of ashuttle pin of a second connector part of the connector. The firstcartridge part may accordingly be sealed against a front portion or tipof the pin and the second cartridge part may be sealed against the frontportion or tip of a shuttle pin.

The chamber may be formed by the first and second cartridge parts suchthat a front face of the pin and a front face of the shuttle pin arelocated within the chamber. The front faces of the pin and the shuttlepin may thus be flushed efficiently, which may avoid that seawater isdragged into the second protection assembly.

The first and second cartridge parts may have an annular shape withannular faces of the first and second cartridge parts facing each otherwhen forming the chamber. The above mentioned sealing element can beprovided on at least one of these annular faces.

The plural flow channels and the inlet and outlet ports can be providedin one of the first cartridge part or the second cartridge part. Byproviding them in only one cartridge part, the other cartridge part canbe of a relatively low complexity. In other embodiments, they may beshared between the two cartridge parts.

The connector may have a first connector part in form of a receptaclepart and a second connector part in form of a plug part. The firstcartridge part may be adapted to be mounted to a protection assembly fora pin of the receptacle part and the second cartridge part may beadapted to be mounted to a front portion or plug nose of the plug partof the connector.

The first cartridge part and the second cartridge part may each have acylindrical opening adapted to allow the passing of a pin of a connectorpart of the connector during mating. In such configuration, a relativelysimple mating mechanism may be employed, while the cartridge isapplicable to a range of subsea connectors.

The sealing portion may comprise a gland type seal, a gland seal or apiston seal. Other seals for providing a sealing between the innercylindrical face of an opening in a cartridge part and the outercylindrical face of a pin can also be used.

The outlet port may be connected to a collection tank for collectingfluid discharged from the chamber formed by the cartridge. Accordingly,if a fluid in the chamber is replaced by a non-seawater medium, such asa dielectric fluid, in particular oil, flushed out medium can becollected in the collection tank, thereby preventing a pollution of thesubsea environment. Similarly, when replacing the non-seawater mediumwith seawater, the flushed out medium can be collected.

The cartridge of the flushing arrangement may be made of a plasticmaterial, in particular a polymer material, e. g. a thermoplasticmaterial. The cartridge may for example be made out of PEEK. In apreferred embodiment, the cartridge is made out of PTFE-loaded PEEK.

At least one part of the cartridge may be sized so as to provide afloating mount in a connector part of the connector. The cartridge maythus accommodate a radial misalignment between the connector part andthe second connector part of the connector during mating. In particular,the entering of a receptacle pin into an opening provided in thecartridge part may be facilitated.

In an embodiment, at least a part of the cartridge is mountable to (orconfigured to be mounted to, or mounted to) a front portion of aconnector part of the connector such that it is exposed to the subseaenvironment when the connector part is deployed subsea. Mounting thecartridge at such position has the advantage that it can be fitted toexisting connectors to provide the connector with the flushingarrangement. Further, a surface of the connector that is exposed toseawater can be flushed, thus preventing the dragging of seawater into aprotected area of the connector, e.g. an area in which the electrical oroptical coupling portions or contacts are located. Front portion of theconnector part refers to a portion that faces the complementaryconnector part during mating, it may for example be the tip of a pin ofa receptacle part or the plug nose of a plug part of such connector.

The surface to be flushed may be an exposed surface that is exposed tothe subsea environment when the connector is deployed subsea. Thecartridge may be adapted to form the chamber around the exposed surface.

The connector may have a first connector part comprising a pin and asecond connector part comprising a shuttle pin. The pin and the shuttlepin may have front faces that are exposed to seawater when the connectoris deployed subsea. The front faces are the faces that face therespective other connector part when the connector parts are mated. Thecartridge may be configured to form the chamber such that the front faceof the pin and the front face of the shuttle pin are located within thechamber. Accordingly, these front faces can be flushed and the trappingof seawater between these front faces during mating can be prevented.

In an embodiment, the plural flow channels comprise an inlet flowchannel connected to the inlet port and an outlet flow channel connectedto the outlet port. They further comprise plural inlet distributionchannels providing flow connections from the inlet flow channel to thechamber and plural outlet collection channels providing flow connectionsfrom the chamber to the outlet flow channel. This way, an effective flowpattern using which the fluid in the chamber can be exchanged almostcompletely by another fluid may be achieved. The inner distributionchannels and the outlet collection channels can be arranged so as tocreate a flow without stagnation points.

The inlet flow channel and the outlet flow channel may be circular flowchannels. The inlet distribution channels and the outlet collectionchannels may comprise radial channels running in a substantially radialdirection. In this way, flow connections can be provided effectivelyinto the chamber, which may have a cylindrical shape.

The cartridge may be formed so as to have an inner cylindrical faceforming a boundary of the chamber, and a fraction, preferably all of theinlet distribution channels can be configured to provide the flowconnections through the inner cylindrical face. A fluid provided via theinlet port can thus be distributed effectively in the chamber. The flowconnections provided by the inlet distribution channels may for examplebe equally spaced in circumferential direction around the innercylindrical face.

The cartridge may be formed so as to have an inner cylindrical faceforming a boundary of the chamber. The plural outlet collection channelsmay comprise a first set of outlet collection channels configured toprovide the respective flow connections through the inner cylindricalface. They may further comprise a second set of outlet collectionchannels configured to provide respective flow connection through anannular face of a first cartridge part of the cartridge facing acorresponding face of a second cartridge part of the cartridge whenforming the chamber. In such configuration, it can be ensured that alsofrom a cavity formed between the two annular faces of the two cartridgeparts and the seal, fluid is effectively removed when flushing thechamber.

In the inner cylindrical face, the flow connections of the inletdistribution channels (may also be termed “inlet distribution ports”)and the flow connections of the outlet collection channels (may also betermed “outlet collection ports”) may be staggered. As mentioned above,these ports may be distributed circumferentially on the cylindricalface.

Some of the inlet distribution channels and/or outlet collectionchannels may be angled so as to create a circular flow within thechamber. In an embodiment, the outlet collection channels of the secondset are angled so as to create a rotational flow in the outlet flowchannel. Accordingly, it may be ensured that also within the outlet flowchannel, which is connected to the outlet port, no stagnation pointsexist.

The cartridge may furthermore be configured such that when installed ona connector part of the connector, a front portion of a pin reachesthrough the first cartridge part, such that the flow connections throughthe inner cylindrical face of the cartridge part are sealed againstambient medium. Accordingly, marine growth which may clog these flowconnections can be prevented when the connector is unmated.

Note that the flushing arrangement in any of the configurationsdescribed herein may be used with embodiments of the above describedconnector.

It is to be understood that the features mentioned above and those yetto be explained below can be used not only in the respectivecombinations indicated, but also in other combinations or in isolation,without leaving the scope of the present invention. In particular, theconnector according to embodiments of the invention may comprisefeatures as described with respect to embodiments of the method and ofthe flushing arrangement, and embodiments of the flushing arrangementmay comprise features described with respect to the connector.

In the following, embodiments of the invention will be described indetail with reference to the accompanying drawings. It is to beunderstood that the following description of the embodiments is givenonly for the purpose of illustration and is not to be taken in alimiting sense. The drawings are to be regarded as being schematicrepresentations only, and elements in the drawings are not necessarilyto scale with each other. Rather, the representation of the variouselements is chosen such that their function and general purpose becomeapparent to a person skilled in the art.

FIG. 1 is a schematic drawing showing a sectional side view of aconnector 100 according to an embodiment of the invention. The connector100 is a wet-mateable subsea connector, i.e. it is adapted to be matedin seawater when deployed at a subsea location. Connector 100 may beadapted to be mated in a water depth in excess of 1,000, 2,000 or even3,000 meters.

Connector 100 has a first connector part 10 in form of a receptacle partand a second connector part 20 in form of a plug part. The receptacle 10has a support 13 from which a pin 12 extends. The pin 12 has a couplingportion 11, which in the embodiment of FIG. 1 is an electrical couplingportion which may be provided as a circumferential electrical contact. Aconductor 14 provides an electrical connection to the cable or thetermination assembly to which the receptacle is mounted. In otherembodiments, an optical coupling portion 11 may be provided forestablishing an optical connection. It is also conceivable tosimultaneously provide electrical and optical coupling portions.

The first connector part 10 further comprises a first protectionassembly 15 which prevents seawater from reaching the coupling portion11 when the first connector part 10 is deployed subsea in an unmatedstate, which is illustrated in FIG. 1. The first protection assembly 15comprises the sliding carriage 16 which is sealed against a frontportion of the pin 12 and further a flexible diaphragm 17. The flexiblediaphragm 17 can be filled with a dielectric liquid and due to itsflexibility has an intrinsic volume compensation functionality. Thesliding carriage 16 can be moved backwards, i.e. away from the frontportion 18 of the pin 12 (also termed “pin tip”), so as to expose thecoupling portion 11. Coupling portion 11 is thus enabled to engage acomplementary coupling portion for making contact. When slidingbackwards, the flexible diaphragm 17 can be folded so as to accommodatethe change in distance/available space. Furthermore, the front portion18 of pin 12 forms part of the protection assembly 15, as it preventsseawater from entering the space enclosed by the diaphragm 17 and thesliding carriage 16.

The second connector part 20 is provided in the form of a plug parthaving a plug body 23 and a front portion of the plug 24 (also termed“plug nose”). In the second connector part 20, a second coupling portion21 is provided, which in the embodiment of FIG. 1 has the shape of acontact sleeve having a compliant component for making contact. Thesecond coupling portion can for example be provided as a socket contact.An electrical conductor (not shown) connected to a subsea cable, a powerdistribution unit or the like is in electrical contact with the secondcoupling portion 21. In the example of FIG. 1, the second couplingportion 21 is an electrical coupling portion; in other embodiments, anoptical second coupling portion may be provided, or even optical andelectrical second coupling portions may be provided. First couplingportion 11 and second coupling portion 21 can be brought into engagementto provide an electrical connection (or an optical connection in case ofoptical coupling portions).

The second connector part 20 further comprises a second protectionassembly 25 which prevents the second coupling portion 21 from beingexposed to seawater. The second protection assembly 25 includes at leastthe front portion 24 of plug body 23 and a shuttle pin 22 which can bepushed back into the plug body 23, so as to expose the second couplingportion 21 during mating. The shuttle pin 22 is sealed against the frontportion 24 of the plug body 23 in the unmated state of the connector100. Just for the purpose of illustration, a spring 26 is shown whichholds the shuttle pin 22 in a sealing engagement with the front portion24 of the plug part 20 in the unmated state.

As can be seen, in the illustrated embodiment, a front portion of thepin 12 and a front portion of the shuttle pin 22, in particular thefront faces 51 of the pin 12 and 52 of the shuttle pin 22 are exposed tothe ambient environment in the unmated condition of connector 100.During mating, the front face 51 of pin 12 is brought into contact withthe front face 52 of shuttle pin 22, the pin 12 pushing the shuttle pin22 into the plug body 23. During such mating operation, seawateradhering to the front faces 51, 52 of the pin 12 and the shuttle pin 22can be dragged into the plug body 23 and can accordingly come intocontact with the first and second coupling portions 11 and 21.Furthermore, part of the surface of pin 12 may be exposed to seawaterduring mating, e.g. after it is exposed by the sliding carriage 16 andbefore it enters the plug body 23 through seal 27. To prevent theingress of seawater, the connector 100 comprises a flushing arrangement30 which is configured to enable the flushing of a surface of theprotection mechanisms 15 and 25, in particular the front face 51 and 52.

In particular, the flushing arrangement 30 is configured to flush thefront face 51 or a front portion 18 (up to the respective seal 33) ofthe pin 12, and a front face 52 or front portion (also up to therespective seal 33) of the shuttle pin 22. The front face 51 of pin 12and the front face 52 of shuttle pin 22 may also be termed “exposedsurfaces”, as they are exposed to seawater in the unmated state of theconnector 100.

In the embodiment of FIG. 1, the flushing arrangement has a firstelement 31, which is mounted to the first connector part 10, inparticular to the sliding carriage 16. It further comprises a secondelement 32 which is mounted to the second connector part 20, inparticular to the front portion 24 of the plug body 23. The firstelement has an annular shape with an inner opening having a cylindricalface. The seal 33 is provided between this inner cylindrical face of thefirst element 31 and the outer cylindrical face of the pin's frontportion 18. The configuration is such that the first element 31 can,together with the sliding carriage 16, slide along the outer surface ofthe pin 12 into a mated position in which the first coupling portion 11is exposed. The seal 33 may for example be some type of gland seal orpiston seal. The first element 31 furthermore has an inlet port 35connectable to a fluid source and an outlet port 36 via which a fluidcan be discharged. It is furthermore provided with flow channels 37 and38.

The second element of the flushing arrangement 30 is sealed against afront portion of the shuttle pin 22 by a corresponding seal 33.Similarly, it has an annular shape with an inner opening, the diameterof which substantially corresponds to the outer diameter of the pin 12and of the shuttle pin 22. A annular front face of the second element 32is provided with a circular seal 34. The seal 34 is set up to providesealing against an annular front face of the first element 31.

Note that “front” has to be understood with respect to the respectiveconnector part 10 or 20. The front of the respective connector part isconsidered to be the part in which the tip of the pin 12, or the tip ofthe shuttle pin 22 is located. Backwardly or rearwardly means towardsthe other end of respective connector part, e.g. towards the support 13for the first connector part 10.

Seal 34 is set up to provide sealing against the front face of the firstelement 31 of the flushing arrangement 30. Since seal 34 is acircumferentially continuous seal, a closed sealed space is formedbetween the first and second elements 31, 32, when the front face of thefirst element 31 and the front face of the second element 32 abut. Achamber is thus formed which is bordered by the first and secondelements 31, 32, a front portion of the pin 12 and a front portion ofthe shuttle pin 22. In this chamber, the front portions of the pin andshuttle pin 12, 22 can be flushed efficiently, as will be describedhereinafter.

Note that although the flushing arrangement 30 of FIG. 1 comprises twoseparate parts 31 and 32, the flushing arrangement may in otherembodiments only have a single independent element 31 or 32, with theother element being part of the respective connector part or protectionassembly. As an example, only a second element 32 may be provided, withthe seal 34 directly sealing against the sliding carriage 16. In evenother embodiments, only the first element 31 may be provided as anindividual element, and the seal 34 may be provided at the front face ofthe first element 31. Sealing may then occur directly against a secondelement comprising e.g. a front face or the front portion 24 of the plugbody 23. Furthermore, the inlet and outlet ports 35, 36 and the flowchannels 37, 38 may be provided in the second element 32, or they may beprovided in both elements 31, 32.

The first and second elements 31, 32 may for example be first and secondcartridge parts of a cartridge. They may be made of a plastic material,in particular a polymer material, e. g. a thermoplastic material. In aparticular configuration, the first and second elements 31, 32 can bemade out of PEEK, preferable PTFE-loaded PEEK.

Other embodiments are certainly conceivable. As an example, the firstand/or second element of the flushing arrangement 30 may not be made ofa plastic material, but of metal. Although in plastic material, morecomplex flow channel structures may be provided, using metal as amaterial for the first and second elements 31, 32 makes the flowarrangement more robust.

FIG. 1 shows the connector 100 in an unmated position, with the firstelement 31 slightly protruding from the front face 51 of the pin 12. Inother embodiments, the first connector part 10 may be configured so thatthe first element 31 of the flushing arrangement 30 is positionedrearwardly of the front face 51 of pin 12, so that the pin 12 slightlyprotrudes from the first element 31. In this way, the flow channels 37,38 are protected and the danger of clogging these channels, e.g. due tomarine growth or dirt, is reduced.

In the schematic diagram of FIG. 2, the connector 100 of FIG. 1 is shownin a first mated state. In the first mated state, the first element 31and the second element 32 of the flushing arrangement 30 are sealedagainst each other by the seal 34, thereby forming a chamber 39. Thechamber 39 is bounded by the first element 31, the second element 32,and the front portions of pin 12 and of receptacle pin 22. The firstelement 31 has an annular front face which faces an annular front faceof the second element 32 on which the seal is provided. Accordingly, thesealing between the first and second elements 31, 32 occurs by seal 34between the two annular front faces. The chamber 39 is thus sealed in aliquid-tight manner against the outside environment, i.e. against theseawater surrounding the first and second connector parts 10, 20 whendeployed subsea. Chamber 39 thus allows the front faces 51, 52 of pin 12and receptacle pin 22 to be flushed, it may also be termed “flushingchamber”.

In the first mated state illustrated in FIG. 2, the first couplingportion 11 is not engaged with the second coupling portion 21. In thefirst mated state, there is accordingly no connection establishedbetween the first and second connector parts 10, 20, but the first matedstate enables the flushing of the exposed surfaces of pin 12 andreceptacle pin 22. It may thus also be termed “flushing state” or“flushing position”.

For flushing, a liquid, in particular a dielectric liquid such as oil isintroduced into the chamber 39 via the inlet port 35 and replaces theseawater that is initially located in the chamber 39. The seawater isdischarged through the outlet port 36 via the outlet channel 38. Theports at the flow channels within the first and/or second elements 31,of the flushing arrangement 30 are configured so as to allow an almostcomplete exchange of the seawater with the non-seawater medium, inparticular with the dielectric liquid during flushing. The flow channelscan be configured so as to create a flow within chamber 39 that has nostagnation points, so that seawater is not trapped at such points. Thismay be achieved by implementing the first and second elements 31, 32 asparts of a cartridge, as described further below. Such cartridge may beused with the present embodiment.

After flushing, seawater will generally no longer adhere to the frontportions of pin 12 and of receptacle pin 22, thus reducing the danger ofseawater being dragged into the plug body 23 in the further matingprocedure.

The first and second connector parts may be held in place in the firstmated position, for example by a mechanical engagement of the frontportion of the plug body with the front portion of the receptacle. Inother embodiments, a mating tool may be used for holding the first andsecond connector parts 10, 20 in the first mated position. Such tool mayfor example be part of an ROV or it may be an ROV-operated tool (notshown). Furthermore, such mating tool may provide the non-seawatermedium to the inlet port 35 and may furthermore comprise a tank fortaking up fluid discharged through the outlet port 36. The mating toolmay comprise corresponding couplings for coupling to the inlet port 35and the outlet port 36.

After flushing is completed (for example after a predetermined amount oftime after which the fluid in chamber 39 is almost completely replacedby non-seawater medium), the connector 100 is brought from the firstmated position illustrated in FIG. 2 into the second mated positionillustrated in FIG. 3. This transition occurs by moving the first andsecond connector parts 10, 20 axially towards each other, i.e. bypushing the plug part 20 into the receptacle part 10 or vice versa.Accordingly, when moving from the first mated position into the secondmated position, the plug body 23 enters the receptacle 19 of the firstconnector part 10. The front portion 24 of the plug body 23 and/or thesecond element 32 push the sliding carriage 16 and the first element 31backwards along the pin 12 so as to expose the first coupling portion11. Simultaneously, the front portion of the pin 12 enters the chamber39 and comes into contact with the front portion of the receptacle pin22. Upon further movement of the first and second connector parts 10, 20towards each other, the pin 12 pushes the shuttle pin 22 into the plugbody 23, the pin 12 moving through the seal 27 and entering the plugbody 23. The pin 12 enters the plug body 23 until it reaches a finalposition in which the first coupling portion 11 is in contact with thesecond coupling portion 21. This final mating state (i.e. fully matedstate or position) is illustrated in FIG. 3.

As can be seen, since the front faces 51, 52 of the pin 12 and thereceptacle pin 22 were flushed prior to moving into the final matedposition, it can be prevented that seawater enters the plug body 23.Furthermore, the surface resistivity of the receptacle pin can bepreserved, which would otherwise be adversely affected by contact withseawater. A high quality and reliable connection can thus be establishedbetween the first and second coupling portions 11 and 21.

When moving from the first mated state of FIG. 2 into the second matedstate of FIG. 3, the pin 12 enters the chamber 39, thus reducing thevolume of the chamber. The flushing arrangement 30 can be provided witha volume compensation device (or volume compensator) which can providecompensation for this change in volume. Several implementations of suchvolume compensator are conceivable. Volume compensation may be achievedby way of certain valves connected to the inlet and/or outlet ports 35,36. As an example, fluid may be allowed to flow out of chamber 39through the outlet port 36 if the pressure inside chamber 39 exceeds thethreshold value. Other devices include a flexible element, such as abladder or bellows, which is in fluid communication with the chamber 39so that it can take up fluid from chamber 39. Thus, a change of theinternal volume of chamber 39 is allowed while maintaining the pressurewithin chamber 39 relatively constant.

FIG. 4 is a schematic drawing showing a subsea connection system 200according to an embodiment of the invention. The subsea connectionsystem 200 may employ a subsea connector 100 in any of theconfigurations described herein. Accordingly, the explanations givenabove with respect to FIGS. 1, 2 and 3 are equally applicable to theconnector 100 of FIG. 4. In FIG. 4, the mating direction of the firstconnector part 10 and the second connector part 20 is indicated by anarrow. On the first connector part 10, the support 13, the pin 12extending forwardly from the support 13 and the receptacle 19 are shown.Furthermore, a volume compensation device 50 is illustrated which isadapted to compensate volume changes of the flushing chamber 39, i.e. totake up a fluid from the flushing chamber 39 when the pin 12 moves intothe flushing chamber 39, as described above. The flushing arrangement 30further comprises a pressure limitation device 60, which is preferablymounted to the connector part on which the inlet port 35 and the outletport 36 are provided.

The inset of FIG. 4 shows an enlarged drawing of a possibleimplementation of the pressure limitation device 60. Pressure limitationdevice 60 is configured to limit the pressure that is present in theflushing chamber 39 during flushing. Thus, it can be prevented that thepressure inside chamber 39 pushes the receptacle pin 22 into the plugbody 23. The pressure limitation device 60 includes a pressure reliefvalve 61 which is connected between the inlet port 35 and the outletport 36. The pressure relief valve 61 has a pressure threshold. Thepressure relief valve 61 is configured to open if the pressure on itsinput side exceeds the pressure threshold. Accordingly, fluid suppliedvia supply line 71 is allowed to flow back via the discharge line 72,thereby preventing a built-up of pressure within the chamber 39. In anormal flushing operation, fluid is supplied to chamber 39 via thesupply line 71 coupled to inlet port 35, and fluid discharged fromchamber 39 via outlet port 36, and flows via discharge line 72 into acollection tank.

FIG. 4 further illustrates a mating tool 210 which assists in the matingprocedure of the first and second connector parts 10, 20. The matingtool 210 in particular performs the flushing operation. For connectingto the supply line 71 and the discharge line 72, the mating tool 210comprises flow connectors 220, which may be provided in the form ofhydraulic couplings. The tool 210 comprises a tank 211 for non-seawatermedium, such as a dielectric liquid, in particular oil, such as siliconoil. During flushing, the non-seawater medium can be supplied via thepump 213 and the supply line 71 into the flushing chamber 39. Duringflushing, seawater and parts of the non-seawater medium are dischargedvia the outlet port 36 and the discharge line 72. The discharged fluidis collected in the collection tank 212 to prevent pollution of thesubsea environment. Each of the tanks 211, 212 may be provided with avolume compensation device 250, so as to compensate for volume changesof the liquid within the tank.

Note that the embodiment of FIG. 4 is only one possible configuration ofthe subsea connection system 200. In other embodiments, the mating tool210 may for example comprise a pump coupled to the discharge line 72, soas to create a negative pressure and to essentially “suck” fluid out ofthe chamber 39 during flushing. The low pressure generated by such pumpwill in the same way lead to a replacement of the fluid inside thechamber 39 by non-seawater medium from tank 211. The advantage of suchconfiguration is that the danger of pushing the shuttle pin 22 into theplug body 23 is reduced, and the system may not require the pressurelimitation device 60.

Furthermore, the subsea connection system 200 can be configured toreplace a fluid in the chamber 39 with seawater prior to de-mating ofthe first and second connector parts 10, 11. For this purpose, themating tool 210 can comprise a seawater inlet port 214, and a controlvalve 215. By replacing the fluid inside the chamber 39 with seawaterprior to de-mating, a pollution of the subsea environment withnon-seawater medium can be prevented.

The mating tool 210 can furthermore comprise a support mechanism forholding the first connector part and the second connector part in thefirst mated position during flushing. It can thus be ensured that thechamber 39 is formed in a safe and secure manner and that a misalignmentof the first and second connector parts 10, 20 and an accidental openingof the chamber can be reduced or prevented. Such mechanical supportmechanism may for example comprise a first mechanical coupling part forsupporting the first connector part 10 at a second mechanical couplingpart for supporting the second connector part 20. The mechanical supportmechanism may in some configurations be configured to bring the firstand second connector parts 10, 20 from the first mated state into thesecond mated state.

The mating tool 210 may form part of an ROV (remotely operated vehicle),or it may be configured as an ROV-tool.

FIG. 5 shows a further embodiment of a connector 100 according to theinvention. Only the front portions of the first and second connectorparts 10, 20 are illustrated in FIG. 5A. Since the connectorconfiguration corresponds in large parts to the one of the connector 100of FIGS. 1 to 4, the explanations given above are equally applicable tothe embodiment of FIG. 5. The protection assembly 15 of the firstconnector part 10 again comprises a front portion of pin 12 and thesliding carriage 16. The protection assembly of the second connectorpart 20 comprises the front portion of shuttle pin 22 and the frontportion of the plug body 23.

In FIG. 5A, the first and second connector parts 10, are shown in aposition prior to forming the flushing chamber 39, i. e. in a positionprior to reaching the first mated state. The first and second elements31, 32 of the flushing arrangement 30 are in FIG. 5 implemented as partsof a cartridge. As can be seen, the first cartridge part 31 is, via thepin seals 33, sealed against the front portion of the pin 12. Similarly,the second cartridge part 32 is sealed against the shuttle pin 22 by thepin seals 33. The second cartridge part 32 comprises the circular seal34, which may also be termed “environmental seal” as it seals, in thefirst mated state, the chamber 39 against the surrounding subseaenvironment.

The first and second cartridge parts 31, 32 are in more detailedillustrated in FIGS. 5B and 5C. FIG. 5B shows the second cartridge part32 including the environmental seal 34 and the pin seals 33. Theenvironmental seal 34 is provided on an annular front face of the secondcartridge part 32. The first cartridge part 31 is illustrated in FIG.5C. The first cartridge part 31 comprises flow channels 37, 38 forgenerating a flow without stagnation points within the flushing chamber39. The first cartridge part 31 includes the inlet port 35 and theoutlet port 36. Inlet distribution channels 37 are provided whichconnect the inner port 36 to the inside of the chamber 39. Furthermore,outlet collection channels 38 are provided through which fluid can leavethe chamber 39. The outlet collection channels 38 are in fluidcommunication with the outlet port 36.

The connector 100 of FIG. 5A is shown in the first mated state in FIG.6. As can be seen, the first and second cartridge parts 31, 32 aresealed against each other by way of the environmental seal 34. Note thatin other embodiments, intervening elements may be provided. As anexample, a locking ring may be provided which locks the first cartridgepart 31 in place in the sliding carriage 16, and the seal 34 may sealagainst such locking ring. In even other embodiments, only one cartridgepart comprising inlet and outlet ports 35, 36 and the flow channels 37,38 may be provided, and may directly be sealed against a component ofthe first or second connector part. FIG. 6 illustrates that in the firstmated state, the chamber 39 is formed between the first and secondcartridge parts 31, 32 and the front portions of pin 12 and of shuttlepin 22.

FIG. 6 furthermore illustrates the flow of fluid into the chamber 39 andout of the chamber 39. Note that although in FIG. 6, the inlet port 35is shown on the upper part of the cartridge and the outlet port 36 isshown on the lower part of the cartridge, these ports may be arrangeddifferently, and the structure of the flow channels 37, 38 may be morecomplex, for example as shown in FIG. 5C or 7 and explained furtherbelow. In this respect, FIG. 6 only schematically illustrates thefunctioning of an exemplary flushing mechanism.

Reference numeral 70 indicates a tolerance in radial direction in themount of the second cartridge part 32 in the front portion of the plugbody 23. In this way, a floating mount is achieved which allows a smallmovement of the second cartridge part 32 in radial direction. This socalled “radial float” can assist the alignment when moving into thesecond mated position, i.e. into the fully mated position, and canreduce the likelihood of seal damage. As an example, when the pin 12moves into the chamber 39 and into engagement with the shuttle pin 22,the radial float allows the second cartridge part 32 to align itselfwith the front portion of the pin 12, so that the alignment of the twopins 12 and 22 can be assisted and that damage to the seals can beprevented. While the environmental seal 34 (which seals between theannular front faces of the first and second cartridge parts 31, 32 andmay thus also be termed “face seal”) is relatively tolerant to a radialmisalignment, a misalignment between the pin 12 and the second cartridgepart 32 may lead to a collision of the pin 12 with a gland seal 33,which can damage the seal. This can be prevented by the radiallyfloating cartridge part 32.

FIG. 7 illustrates a first element 31 of a flushing arrangement 30,which is implemented as a first cartridge part. As mentioned above, theflushing arrangement 30 may comprise a complementary second cartridgepart, or only the first cartridge part may be provided and may be sealedagainst a surface of the second connector part. In other embodiments,the first cartridge part may be provided in the second connector partand may be sealed against a surface of the first connector part oragainst a second cartridge part mounted to the first connector part.

The first cartridge part 31 of FIG. 7A has an annular shape with athrough hole or opening 45 through which the pin 12 reaches duringmating. The opening 45 is bounded by an inner cylindrical face 46. Theinner cylindrical face comprises a sealing portion 48 which is adaptedto be sealed against a part of the connector 100, in particular againsta surface to be flushed. As outlined with respect to the aboveembodiments, the surface to be flushed may be a surface on a frontportion of the pin 12, and accordingly, the sealing portion 48 can beadapted to be sealed against a front portion of the pin 12. Thecartridge part 31 may furthermore comprise seals provided in the sealingportion 48, it may for example comprise the above mentioned pin seals33. In other embodiments, the sealing portion 48 may be provided at adifferent location, for example at an annular back face of the cartridgepart 31, e.g. for sealing against the sliding carriage 16 or against afront surface of the plug body 23. In even other embodiments, thesealing portion 48 may be adapted for a sealing against a front portionof the shuttle pin 22.

With respect to FIGS. 7A to 7C, the flow channels that were only shownand described in a simplified configuration with respect to the FIGS. 1to 6 are now explained in more detail. The flow channels 37, 38 comprisean inlet flow channel 41 which has a fluid connection to the inlet port35. The inlet flow channel 41 is a circular flow channel extendingcircumferentially in the annular body of the first cartridge part 31.Furthermore, an outlet flow channel 43 connected to outlet port 36 isprovided which similarly has a circular shape and extendscircumferentially in the body of the first cartridge part 31. The inletflow channel 41 may also be termed “inlet ring”. The outlet flow channel43 may also be termed “outlet or exhaust ring”.

As can be seen in the sectional side view of FIG. 7A, the inlet flowchannel 41 and the outlet flow channel 43 may be arranged at the sameradial distance, yet they may in other embodiments be arranged atdifferent radial distances. Accordingly, in the sectional top view ofFIG. 7B, the inlet flow channel 41 and the outlet flow channel 43 lieabove each other, so that only one of them is visible.

As already illustrated in FIG. 7A, plural inlet distribution channels 42are formed in the first cartridge part 31 and provide a flow connectionbetween the inlet flow channel 31 and the interior of the opening 45,which in operation can form the flushing chamber 39. FIG. 7B, in whichthe inlet flow channel 41 is not visible, shows that the inletdistribution channels 42 provide the flow connection through thecircumferential inner face 46 of the opening 45. The ports formed by theflow channels 42 ending in the inner cylindrical face 46 may be termed“inlet distribution ports”. As shown in FIG. 7B, the inlet distributionchannels 42 and the corresponding inlet distribution ports may bedistributed around the opening 45, and they may be spaced equidistantlyin a circumferential direction. As indicated by arrows, fluid can thusbe injected into a chamber formed by the opening 45 from differentpositions around the inner cylindrical face 46 bounding the chamberduring flushing.

In order to create a turbulent flow without stagnation points, outletcollection channels 44 are provided which provide a fluid connectionfrom the opening 45 to the outlet flow channel 43, as shown in FIG. 7B.Besides this first set of outlet collection channels 44, a second set ofoutlet collection channels 47 can be provided which terminate in theannular front face of the first cartridge part 31. The flow connectionsthrough the inner cylindrical face 46 and through the annular front faceof the first cartridge part 31 may be termed “outlet collection ports”.As shown in FIG. 7B, the first and second sets 44 and 47 of outletcollection channels are again distributed around the opening 45 and arespaced equidistantly in circumferential direction. The inletdistribution channels 42 and the first set of outlet collection channels44 may for example be provided in a staggered configuration so as tocreate a flow with relatively high turbulences. Accordingly, nostagnation points form within the opening 45 during flushing.

Furthermore, the outlet collection ports of the second set of outletcollection channels 47 can be placed relatively close to the area inwhich the sealing by seal 34 is provided, as illustrated in FIG. 4C.Accordingly, also liquid which may be trapped between the two frontfaces of the two opposing cartridge parts can be removed efficientlyfrom the flushing chamber 39 formed between the cartridge parts (orbetween a cartridge part and another surface, e.g. plug front face).

Furthermore, the outlet collection channels 47 may be provided at anangle, so as to cause a clockwise or anti-clockwise flow in the outletflow channel 43.

FIG. 7B indicates by arrows the primary flow of fluid. The fluid entersthe inlet ring 41 tangentially via the inlet port which may be connectedat an angle. This can cause a clockwise or anti-clockwise fluid flow inthe inlet ring 41. The fluid exits the inlet ring 41 via the radialinlet distribution channels 42 which direct the flow over the receptaclepin tip and towards the pin centre during flushing. By way of multipleflow paths towards the centre, turbulence can be caused and stagnationof fluid prevented. This removal of liquid from the chamber 39 occursvia the outlet collection channels 44 which are aligned essentiallyparallel to the radial inlet distribution channels 42. As indicated byarrows, the flow is guided into the outlet ring 43. The outletcollection ports increase the turbulence in the flow. A secondary flowis created towards the annular front face of the first cartridge part 31towards the sealing surface for the seal 34, which is indicated in FIG.7C. The flow is directed into the outlet ring 43 by way of the secondset of outlet collection channels 47. The second set of channels 47creates a clockwise or anti-clockwise flow in the outlet ring 43, whichcan be connected to the outlet port 36 by a tangentially orientedgallery, thus facilitating the discharging of fluid.

Note that FIGS. 7A to 7C show only one possible implementation of thefirst cartridge part 31 of the flushing arrangement 30. In otherembodiments, a different configuration of the flow channels can beprovided. Preferably, the flow channels are arranged such that in theflushing chamber formed by the first cartridge part 31, a flow withrelatively high turbulence and without stagnation points is created.

Besides the first cartridge part 31, the flushing arrangement 30 cancomprise further elements, such as the second cartridge part 32, whichis described further above, e.g. with respect to FIG. 5B.

It should be clear that the first cartridge part 31 may be used in anyof the above described embodiments of the connector 100, it may forexample be used for the first element 31 or the second element 32 of theflushing arrangement 30 of the respective connector.

FIG. 8 shows a flow diagram of a method according to an embodiment ofthe invention. In a first step 301, the first and second connector partsof the subsea connector 100 are provided in a subsea location. In thenext step 302, the first and the second connector parts are brought intoa first mated position in which the first coupling portion 11 and thesecond coupling portion 21 are disengaged. A mating tool 210 asdescribed with respect to FIG. 4 may for example be used for bringingthe connector parts into the first mated position and for holding themin this position.

When bringing the first and second connector parts into the first matedposition, a flushing chamber 39 is formed by way of the first cartridgepart 31 and the second cartridge part 32 (step 303). Since the chamberis formed in a subsea environment, it will initially be filled withseawater. In step 304, the seawater in the chamber is displaced byfilling the chamber through an inlet port of the cartridge with anon-seawater medium, in particular with a dielectric liquid. In thisway, the front faces of the pin 12 and of the shuttle pin 22 areflushed.

In step 305, the first and second parts are brought into the secondmated position by axial movement of the first connector part and thesecond connector part towards each other. Depending on theconfiguration, either the first connector part or the second connectorpart may be mounted, e.g., to a step plate, termination unit or thelike, and the respective other connector part may be moved into furtherengagement to reach the second mated position. By bringing the first andsecond connector parts into the second mated position, the firstcoupling portion is engaged with the second coupling portion to form anelectrical or optical connection. As outlined further above, in someembodiments, an electrical and an optical connection may be formed.

By way of such method, a relatively simple mating of the first andsecond connector parts can be achieved, while there is essentially noexposure of the coupling portions of the first and second connectorparts to seawater. Mating can occur in a clean environment, and due tothe protection of the first and second coupling portions, marine growthand a degradation of the connection can be prevented.

The above described method may be performed with any of the embodimentsof the connector 100 and of the subsea connection system 200 describedabove.

As can be seen from the above, by way of the flushing arrangement, it ispossible to displace seawater from the front portions of the pin and theshuttle pin, whereby surface resistivity of the pin can be preserved asit passes through the plug body during the mating procedure.

Accordingly, problems which can occur due to a reduction in surfaceresistivity due to seawater, such as reduced connector performance inparticular at elevated voltages can be mitigated or even prevented. Byway of the above described cartridge, it is possible to promote aturbulent flow and to prevent stagnation points, so that an almostcomplete and reliable displacement of seawater can be obtained. Thematerial of the cartridge and the seals prevents marine growth on thesealing surfaces, so that the sealing performance does not degradesubstantially over time. The ingress of seawater into the flushingchamber may thus be prevented. The material of the cartridge alsoenables the use of the above described flow channel structure.Furthermore, the flushing chamber has a relatively low volume, whichminimizes the use of non-seawater medium and furthermore reduces theeffort required to clean the exposed surfaces to a relatively highstandard.

The cartridge as described above may in addition provide an additionalbarrier to seawater in an area of the respective connector part which istraditionally prone to high electrical stresses. Also, since a cartridgeis used, relatively little modification on the respective connector partis necessary. The connector remains functional even without the use ofthe flushing arrangement, the cartridge may for example be replaced by adummy cartridge for applications which are less critical with respect tothe contact with seawater.

While specific embodiments are disclosed herein, various changes andmodifications can be made without departing from the scope of theinvention. The present embodiments are to be considered in all respectsas illustrated at non-restrictive, and all changes coming within themeaning and equivalency range of the appended claims are intended to beembraced therein.

The invention claimed is:
 1. A flushing arrangement for flushing a surface of a wet-mateable connector for subsea use, the surface being exposed to seawater when the connector is deployed subsea, the flushing arrangement comprising: an inlet port to receive a fluid from a fluid source and an outlet port to discharge a fluid; a cartridge adapted to form a chamber around the surface to be flushed prior to flushing, wherein the cartridge includes a sealing portion adapted to be sealed against a part of the connector, the cartridge including plural flow channels formed in said cartridge, said plural flow channels comprising flow channels to provide a fluid connection between the inlet port and the chamber to enable a flow of fluid into the chamber and flow channels to provide a fluid connection between the chamber and the outlet port to enable a flow of medium out of the chamber, wherein the cartridge does not form part of a housing of the connector, and wherein the cartridge is mountable to a front portion of a connector part of the connector so as to be exposed to the subsea environment when the connector part is deployed subsea.
 2. The flushing arrangement of claim 1, wherein the outlet port is connectable to a collection tank for collecting fluid discharged from said chamber.
 3. The flushing arrangement of claim 1, wherein the surface to be flushed is an exposed surface that is exposed to the subsea environment when the connector is deployed subsea, the cartridge being adapted to form said chamber around said surface.
 4. The flushing arrangement of claim 1, wherein the connector has a first connector part comprising a pin and a second connector part comprising a shuttle pin, the pin and the shuttle pin having front faces that are exposed to seawater when the connector is deployed subsea, wherein the cartridge is configured to form the chamber such that a front face of the pin and a front face of the shuttle pin are located within said chamber.
 5. The flushing arrangement of claim 1, wherein said sealing portion is provided on an inner cylindrical face of the cartridge and is adapted to provide sealing against an outer cylindrical face of a pin of a connector part of said connector.
 6. A connector for subsea use, the connector including a first connector part and a second connector part adapted to be mated subsea, the connector comprising: a first coupling portion arranged in the first connector part; a second coupling portion arranged in the second connector part, wherein the first and second coupling portions are configured to be brought into engagement for establishing an electrical or optical connection when the first connector part and the second connector part are mated, and wherein the first and second coupling portions are protected from exposure to seawater when the connector is unmated and deployed subsea by first and second protection assemblies; and the flushing arrangement of claim
 5. 7. The flushing arrangement of claim 5, wherein said sealing portion and said inner cylindrical face form part of a first cartridge part of the cartridge, and wherein a second cartridge part of the cartridge comprises a second inner cylindrical face and a second sealing portion adapted to provide sealing against an outer cylindrical face of a shuttle pin of a second connector part of said connector.
 8. The flushing arrangement of claim 3, wherein said chamber is formed by the first and second cartridge parts such that a front face of the pin and a front face of the shuttle pin are located within said chamber.
 9. The flushing arrangement of claim 1, wherein said cartridge includes a first cartridge part adapted to be mounted to a first connector part and a second cartridge part adapted to be mounted to a second connector part of said connector, the flushing arrangement further comprising a sealing element configured to provide a liquid tight seal between said first cartridge part and said second cartridge part when forming said chamber.
 10. The flushing arrangement of claim 9, wherein said first and second cartridge parts have an annular shape with annular faces of the first and second cartridge parts facing each other when forming said chamber, the sealing element being provided on at least one of said annular faces.
 11. The flushing arrangement of claim 9, wherein the plural flow channels and the inlet and outlet ports are provided in one of the first cartridge part or the second cartridge part.
 12. The flushing arrangement of claim 9, wherein the connector includes a first connector part in form of a receptacle part and a second connector part in form of a plug part, wherein the first cartridge part is adapted to be mounted to a protection assembly for a pin of the receptacle part and wherein the second cartridge part is adapted to be mounted to a plug nose of the plug part of the connector.
 13. The flushing arrangement of claim 9, wherein the first cartridge part and the second cartridge part each include a cylindrical opening adapted to allow the passing of a pin of a connector part of said connector during mating.
 14. The flushing arrangement of claim 1, wherein said plural flow channels comprise an inlet flow channel connected to the inlet port and an outlet flow channel connected to the outlet port, and further comprise plural inlet distribution channels providing flow connections from the inlet flow channel into the chamber and plural outlet collection channels providing flow connections from the chamber to the outlet flow channel.
 15. The flushing arrangement of claim 14, wherein said cartridge is formed so as to have an inner cylindrical face forming a boundary of said chamber, and wherein said outlet collection channels comprise a first set of outlet collection channels configured to provide said flow connections through said inner cylindrical face and a second set of outlet collection channels configured to provide said flow connections through an annular face of a first cartridge part of said cartridge facing a corresponding face of a second cartridge part of said cartridge when forming said chamber.
 16. A connector for subsea use, the connector including a first connector part and a second connector part adapted to be mated subsea, the connector comprising: a first coupling portion arranged in the first connector part; a second coupling portion arranged in the second connector part, wherein the first and second coupling portions are configured to be brought into engagement for establishing an electrical or optical connection when the first connector part and the second connector part are mated, and wherein the first and second coupling portions are protected from exposure to seawater when the connector is unmated and deployed subsea by first and second protection assemblies; and the flushing arrangement of claim
 1. 17. The connector according to claim 16, wherein at least a part of the cartridge is mounted to the first or second protection assembly to provide flushing of a surface of the respective protection assembly that is exposed to seawater when the connector is deployed subsea.
 18. The flushing arrangement of claim 1, wherein the plural flow channels are configured to generate a flow without stagnation points in said chamber when providing a fluid via said inlet port.
 19. The flushing arrangement of claim 18, wherein said sealing portion is provided on an inner cylindrical face of the cartridge and is adapted to provide sealing against an outer cylindrical face of a pin of a connector part of said connector.
 20. A connector for subsea use, the connector including a first connector part and a second connector part adapted to be mated subsea, the connector comprising: a first coupling portion arranged in the first connector part; a second coupling portion arranged in the second connector part, wherein the first and second coupling portions are configured to be brought into engagement for establishing an electrical or optical connection when the first connector part and the second connector part are mated, and wherein the first and second coupling portions are protected from exposure to seawater when the connector is unmated and deployed subsea by first and second protection assemblies; and the flushing arrangement of claim
 18. 21. The flushing arrangement of claim 9, wherein said sealing portion and said inner cylindrical face form part of the first cartridge part, and wherein the second cartridge part comprises a second inner cylindrical face and a second sealing portion adapted to provide sealing against an outer cylindrical face of a shuttle pin of a second connector part of said connector.
 22. The flushing arrangement of claim 21, wherein said chamber is formed by the first and second cartridge parts such that a front face of the pin and a front face of the shuttle pin are located within said chamber.
 23. The flushing arrangement of claim 1, wherein said sealing portion includes a seal.
 24. The flushing arrangement of claim 23, wherein said a seal is a gland type seal, a gland seal or a piston seal.
 25. The flushing arrangement of claim 1, wherein said cartridge of the flushing arrangement is made of a plastic material.
 26. The flushing arrangement of claim 25, wherein said plastic material is a polymer material, such as PEEK.
 27. The flushing arrangement of claim 25, wherein said polymer material is PEEK.
 28. The flushing arrangement of claim 14, wherein said cartridge is formed so as to have an inner cylindrical face forming a boundary of said chamber, and wherein at least a fraction of said inlet distribution channels are configured to provide said flow connections through said inner cylindrical face.
 29. The flushing arrangement of claim 28, wherein said cartridge is formed so as to have an inner cylindrical face forming a boundary of said chamber, and wherein said outlet collection channels comprise a first set of outlet collection channels configured to provide said flow connections through said inner cylindrical face and a second set of outlet collection channels configured to provide said flow connections through an annular face of a first cartridge part of said cartridge facing a corresponding face of a second cartridge part of said cartridge when forming said chamber. 